TerminateProcess

TerminateProcess is a Windows API function used to immediately terminate a specified process and all of its threads. It is provided by the Windows operating system to end a running process from another process or from a debugger.

The function signature is BOOL TerminateProcess(HANDLE hProcess, UINT uExitCode). The hProcess parameter must be a handle to the target process with PROCESS_TERMINATE access. The uExitCode parameter specifies the exit code that will be assigned to the terminated process.

Behavior and safety considerations: TerminateProcess ends the target process abruptly, without giving the process a chance to perform normal cleanup, finalize I/O, or run termination handlers. As a result, resources allocated by the process may remain allocated until the system reclaims them, and state may be left inconsistent. Because threads within the process are terminated as a group, there is no opportunity for graceful shutdown. Use of TerminateProcess is therefore considered dangerous and should be limited to emergency or unresponsive scenarios where other termination methods are not feasible.

Return value and errors: The function returns a nonzero value if the termination succeeds; otherwise it returns zero. Call GetLastError for extended error information if it fails. Common error conditions include ERROR_ACCESS_DENIED (insufficient privileges), ERROR_INVALID_HANDLE (invalid process handle), or ERROR_INVALID_PARAMETER.

Related concepts: For a graceful shutdown, other mechanisms such as sending a close message to a user interface, or having the process exit itself via ExitProcess, are preferred. TerminateProcess differs from ExitProcess in that the latter is invoked by the process itself to terminate cleanly, while the former terminates a process from the outside.